Where is the impulse delayed before continuing to the ventricles?

The impulse is delayed at the AV (atrioventricular) node before continuing to the ventricles. This delay is crucial for coordinating the timing of the heart's contractions.

Specifically, after the electrical impulse is initiated in the SA (sinoatrial) node, it travels through the atria, causing them to contract and push blood into the ventricles. The AV node serves as a critical checkpoint between the atria and ventricles. Its role is to slow down the impulse before it is transmitted to the ventricles via the bundle of His and Purkinje fibers. This delay allows the ventricles enough time to fill completely with blood from the atria before they contract. If the impulse did not experience this delay, the ventricles would not fill adequately, compromising the efficiency of blood circulation.

Other structures, such as the SA node, primarily function to initiate and regulate the overall heart rate, while the Purkinje fibers are responsible for distributing the impulse throughout the ventricles after it has passed through the AV node. The heart apex does not play a role in delaying the impulse; rather, it is the site from which the contraction spreads through the ventricles. Thus, the AV node is essential for ensuring proper cardiac function through